Improvement in sewing-machines



c. s. CUSHMAN. SEWING-MACHINE.

N-PEIEHS, PHOTO-LITHOGRAPHER WASHINGTON, n O.

Patented K011631875.

LINITED STATES PATENT. QFFIGE.

CYRUS OUSHMAN, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 169,965, dated November 16, 1875; application filed June 26, 1875.

To all whom it may concern:

Be it known that I, OYRUs S. GUSHMAN, of the city and county of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in Sewing-Machines, of which the following is a specification:

The object of my invention is to provide a simple and efficient device for operating the shuttle-lever and feed-shaft of a sewingmachine; to which ends my improvements consists in certain novel combinations of an operating eccentric, and its strap and rod,

with a vibrating shaft, guide, shuttle-lever,

connecting-link, and feed-shaft, as hereinafter fully set forth.

In the accompanying drawing, Figure l is a side view of so much of a sewing-machine as is sufficient to exemplify myimproveinents; Fig. 2, an inverted plan view of the same; Fig. 3, a vertical transverse section of the same at the line as w of Fig. 1; and Fig. 4. a partial top view, with the frame in section.

My improvements are shown as applied to a machine, the bed-plate A, needle-arm B, main-shaft 0, and balance-wheel and pulley 0 of which are of the ordinary construction. To carry out the objects of my invention I provide a vertical rock-shaft, D, the upper end of which is journaled in the needlearm B, and the lower in a bearing, D, a projection of the needle-arm extending below the bed-plate. Set-screws d and d at its upper 'and lower ends, respectively, enable lost motion at these points to be taken up' when required. The rock-shaft D is provided with an aperture near its upper end to allow the driving-shaft O to pass through it, and is provided with projecting jaws d d, which embrace the strap or tablet E of an eccentric, 0 mounted upon said shaft. The sides of the tablet E are segments of a cylinder, and the inner faces of the jaws (l d are correspondingly curved to fit over them. The vertical length of the curved sides of the cocentric'strap must be sufficiently great to enable the jaws d d to remain in contact with them during the entire traverse of the eccentric. The eccentric rod E, which is firmly secured to the tablet E, passes through a guide, D projecting from the rock-shaft D, and has a stud, e, projecting from it at right angles near its lower end. The guide D may be provided with a slot and screw for taking up lost motion, if desired. The sh utt-le-lever D is permanently secured to the rock-shaft above its lower journals, so as to vibrate horizontally beneath the bed-plate A.

A feed-shaft, F, is mounted horizontally in bearings beneath the bed-plate, and carries upon its end nearest the rock-shaft a crankwheel, G, and a cam, I, for operating the feed-motion upon its opposite end. A crankpin, g, upon the wheel G, is connected by a link, H, with the stud c of the eccentric rod E.

In the operation of the machine the rotation of the driving-shaft (J and its eccentric G will impart an oscillating or vibrating movement to the rock shaft D, and, consequently, to the shuttle-lever D attached thereto, [by reason of the relative arrangement of the jaws d d of the rock-shaft and the curved-sided eccentric strap E. The traverse of the eccentric will, at the same time, impart a vertical movement to its rod E, which, being governed by the guide D on the rock-shaft D, is thereby caused to vibrate with said shaft, as well as to move in a vertical line. Thesercoinbined movements of the eccentric rod impart a vibrating or oscillating movement to the feed-shaft F through the medium of the connecting-link H.

The arrangement herein described provides only for an oscillation or partial rotation of the feed-shaft, but the latter may be rotated entirely around its center by a different relative location of the parts and the provision of a rigid connection, instead of a pivoted one, between the link H and the eccentric rod.

It will be seen that the mutual action of the device specified operates both the shuttlelever and feed-shaft with direct connections and simple mechanism.

I claim as my invention, and desire to seicure by Letters Patent-- 1. The combination of the operating eccentric, the cylindrically-sided strap, and the eccentric rod, with the vibrating rock-shaft, shaft, substantially as and for the purpose setthe jaws embracing the strap and the guide forth. for the eccentric rod, substantially as set forth OYRUS'S. GUSHMAN.

2. The combination of a feed-shaft and an Witnesses;

eccentric rod, with a vibrating rock-shaft J. SNQWDEN BELL,

and an eccentric arranged upon the driving- CHAS. W. SGHUELLERMANN. 

